L-phenyl-3,4-dihydronaphthalene

The crude mixture was monitored by chiral stationary phase (CSP) HPLC (eluent hexane/isopropanol 95/5, 0.5mLmin, Chiralcel OD-H). After 2 h, (i/f,25)-l-phenyl-3,4-dihydronaphthalene oxide (80% ee) was obtained as the major enantiomer (fR=13.9 min) with 100% conversion (calculated using the internal standard) the minor 1S,2R) enantiomer eluting first (rR=10.1 min). 

Catalyst 33a was subsequently used to epoxidize several other olefins. Again, the reactivity of the catalyst at (5 mol%) was good, but a wide range of ees was observed (Table 5.6). l-Phenyl-3,4-dihydronaphthalene was epoxidized with high enantioselectivity (95% ee and 66% yield after 35 min). 4-Phenylstyrene oxide was produced with 29% ee, one of the highest reported ees for the epoxidation of terminal alkenes using iminium salt catalysis. 

These olefins were not as reactive towards catalyst (31) as the previously tested substrate 1-phenylcyclohexene, therefore the majority of reactions were carried out at —40 °C. Again, the dichloro methane/acetonitrile conditions produce the better results in terms of both enantiomeric excess and epoxide conversion, over the dichloromethane conditions. Triphenylethylene was extremely unreactive when compared with all the other alkenes tested (entries 3, 4, 10 and 11). The best ee obtained was for l-phenyl-3,4-dihydronaphthalene at —40 °C in dichloromethane/acetonitrile, which in 3h gave 100% conversion and 65% ee. This is even more remarkable when one considers that l-phenyl-3,4-dihydro-naphthalene also gave the poorest result in dichloromethane (7% ee). 

Between 2000 and 2005, several major reviews on asymmetric organic synthesis were published [10-14] which also covered some advances in the dynamic field of polymer-immobilized manganese-saien complexes. In 2000, immobilization of Jacobsen s epoxidation catalyst [26] on polystyrene and polymethacrylate resins was reported [27]. Catalytic performances were evaluated using 1,2-dihydronaphtha-lene, indene, l-phenyl-3,4-dihydronaphthalene and 1-phenylcyclohexene as substrates, and wx-chloroperbenzoic add (m-CPBA) and N-methylmorpholine-N-oxide (NMO) as oxidant/co-oxidant. Epoxide yields up to 61% and ee values up to 91%... 

Bulman Page and coworkers have optimized conditions for the use of their 5-amino-2,2-dimethyl-4-phenyl-l,3-dioxane derived imminium salt catalyst 66, and introduced two new analogues (Figure 26) for asymmetric epoxidation. 1-Phenyl cyclohexene and 1-phenyl 3,4-dihydronaphthalene are epoxidized in up to 89% ee <2007JOC4424, 2007T5386>. 

Photoamination of 1,1-diphenylethene (4a) and 1,1-diphenyl-l-propene (4b) with RNHj in the presence ofp-DCB gave the corresponding Type /aminated products (23) (Scheme 6.22) [46], The yields of 23 were poor along with the formation of the minor products (Table 6.5). It was noteworthy that photoaminations of 4a and 4b with r-butylamine gave mainly the acetonitrile-incorporated products, 4,4-diphenylbutanenitrile (24a) and 4,4-diphenyl-3-methylbutanenitrile (24b). Photoamination of 1-phenyl-3,4-dihydronaphthalene (4c) with RNHj gave 2-alkylamino-l-phenyl-l,2,3,4-tetrahydronaphthalene in a mixture of cis and trans isomers. 

Perchloro-l,2,3,-triphenyl-3,4-dihydronaphthalene does not give a qui-none, but indenone [45] instead (27) (Armet, 1978). This result is consistent with the assumption that nucleophilic attack at the initial carbenium centre on the phenylated ring and at C(8) of the nonphenylated ring are sterically hindered. Consequently, the o-quinone [44] is presumably formed, and this undergoes oxidation and degradation, as in the first example. 

Chloro-3,4-dihydronaphthalene-2-yl)methylene]amino -1 -phenyl-2-thioxo-1,6- dihydro[l,3]thiazolo[5,4-d]pyrimidin-7(2H)-one, which considered as a 7-thia analogue of the natural purine bases, adenine and guanine, was prepared in an excellent yield by condensing 189 with cyanoacetic acid hydrazide followed by Gewald reaction, by reaction of 190 with suhar and phenyl isothiocyanate in the presence of triethylamine as a basic catalyst to give 191(Scheme 84). Thiazolo[5,4-d]pyrimidinone derivative 192 was prepared by heating 191 with a mixture of triethylorthoformate and acetic anhydride (1 1) [117],... 

Heterocycles Both non-aromatic unsaturated heterocycles and heteroaromatic compounds are able to play the role of ethene dipolarophiles in reactions with nitrile oxides. 1,3-Dipolar cycloadditions of various unsaturated oxygen heterocycles are well documented. Thus, 2-furonitrile oxide and its 5-substituted derivatives give isoxazoline adducts, for example, 90, with 2,3- and 2,5-dihydro-furan, 2,3-dihydropyran, l,3-dioxep-5-ene, its 2-methyl- and 2-phenyl-substituted derivatives, 5,6-bis(methoxycarbonyl)-7-oxabicyclo[2.2.1]hept-2-ene, and 1,4-epoxy-l,4-dihydronaphthalene. Regio- and endo-exo stereoselectivities have also been determined (259). 

When l,4-dihydronaphthalen-l,4-imine (2) was first obtained via the hydrobromide (113), it was shown to react with phenyl azide to give an adduct (127). The analogous phenyl azide adduct (128) from compound 103 has been better characterized. Naphthalen-l,4-imines also add diazomethane across the 2,3-double bond, forming pyrazolines, e.g., 104 -> 129, two of which have been photolyzed to give the corresponding cyclopropane derivatives (130) with extrusion of nitrogen. ... 

The simple structures of THF-solvated 2,6-di(l-naphthyl)phenyllithium and 2,6-di(phenyl)phenyhithium have been reported to be respectively mono- and dinuclear. The solid-state structure of (DME Li)2C4(SiMc3)4 has recently been found to incorporate DME-chelated metal centres above and below a four-membered, flat cyclobutadienyl ring (within which mean O-C = 1.495 A). A similar structure has also been revealed for (DME Li)2C4Ph2(SiMe2CH2)2. The two electron reduction of 2,3-bis(dimethylsilyl)-l,l,4,4-tetramethyl-l,4-disila-1,4-dihydronaphthalene using elemental lithium affords a complex in which the two metal centres bridge an isolated C = C bond. In the same way, alkali metal ions reside above and below each of two C=C interactions in the tetrametal salt which results from the treatment of 2,3,6,7-tetrakis(trimethylsilyl)-l,l,4,4,5,5,8,8-octamethyl-1,4,5,8-tetrasila- 1,4,5,8-tetrahydroanthracene with Li(0). ... 

A stereochemically interesting observation was made by Carrie s group (Vebrel et al., 1987) in their investigations of diazomethane cycloaddition to methyl l,2-dihydronaphthalene-3-carboxylates substituted at the 1- or 2-position by alkyl or phenyl groups. The 4,5-dihydro-3//-pyrazoles were isomerized into the l//-isomers for easier identification by NMR spectroscopy, in part also by X-ray analyses (6-33). 

---